Always Sometimes Nightmares is a small GZDoom gameplay mod with a simple premise: spawning Nightmare variants of the familiar monsters. Inspired by the Nightmare Imps and Demons in Doom 64, the mod aims simply to provide a small degree of variety and extra challenge by turning some demons in a given map into slightly more lethal versions of themselves.
Map shown: MAP11 of Final Doom: Plutonia Experiment by Milo & Dario Casali